I have a 7 inch "full range" driver and a small tweeter that I'd like to mount coaxially in front of the full ranger, something like the following:

From my reading, an obstruction with a size less than the wavelength of interest is basically invisible, as the sound wave will diffract around the object.

In my case, the size of the tweeter is about 4 cm and therefore theoretically should not affect the output of the full-range until around 6000 Hz. Do you think that mounting the tweeter in this manner will be detrimental to the sound of the full range driver?

I was also thinking of adding a layer of absorptive material to the back of the tweeter to reduce high-frequence reflections.

Thanks,
Eric

(P.S. planet10, the drivers look great and were packed superbly. Cheers.)

Originally posted by Serow
In my case, the size of the tweeter is about 4 cm and therefore theoretically should not affect the output of the full-range until around 6000 Hz. Do you think that mounting the tweeter in this manner will be detrimental to the sound of the full range driver?

I was also thinking of adding a layer of absorptive material to the back of the tweeter to reduce high-frequence reflections.

The results from the arrangement in the picture would be very poor.
But you say your tweeter is only 4cm diameter which should be OK.

One option is to remove the drivers dustcap and mount the tweeter
on an extended pole piece, airflow needs to be smooth.

But there are cogent reasons not to mount the tweeter in such
a fashion if you are running the main driver full range without a
crossover.

I've got a set of 8" whizzer full rangers, i was going to play with co-axially mounting the same tweeters to.

I was thinking of just building an "H-shaped" cross piece which the tweeter sits in the middle of, and adding ductseal to the back of the T to give it a nice smooth shape (even naked they aren't a bad shape). This assembly would then just velcro to the cabinet. I'll also probably continue my tweeter phase plug experiments with these.